Rotary fan



(No Model.)

B. P. PERKINS.

ROTARY PAN.

Patented Ja.11.`28, 1890.

UNITED STATES PATIENT @Finca BENJAMIN n. PERKINS, F I-IoLYoI'rn,MnssAoIIIIsnTTs.`

ROTARY FAN. I

SPECIFICATION forming part of Letters Patent No. 420,310, dated January28, 1890.

Application filed June 25, 1889. Serial No. 315,526. (No model.)

To all whom it may concern:

Beit known that I, BENJAMIN F. PERKINS, a citizen of the United States,residing at Holyoke, in the county of Hampden and State ofMassachusetts, have invented new and useful Improvements in Rotary Fans,of which the following is a specification.

This invention relates to improvements in rotary fans, the purposethereof being to secure an improved construction of blade, whereby suchblade is of the utmost strength and rigidity, and whereby in Vthe use ofthe fan the greatest possible air-current may be produced; and theinvention consists in a rotary fan having peculiarly-formed blades,

all substantially as will hereinafter more fully y appear, and be setforth in the claims.

In the accompanying drawings, in which a fan constructed in accordancewith this invention is illustrated, Figure l is a perspective view ofthe fan. Fig. 2 is alongitudinal sectional view of one of the blades;and Fig. 3 is a viewin the nature of a diagram to illustrate theair-forcing action of a fan-blade with relation to the length of theusual cylindrical casing, which in this figure is also shown, the samein Fig. l having been omitted.

The fan A comprises a hub a, mounted on the driving or driven shaft b,the arms d, ra-

dially projecting from said hub, and the fan blades or wingsf, securedon said radial arms and arranged in a plane oblique both to the axis andthe plane of rotation of the fan. Each blade *is of `quite a slightWidth at its end near the hub, whence it widens to its outer end, whichend is preferably of arc form, as shown. Both side and outer endportions of the fan-blade are bent to one side angularly to the plane ofthe intermediate and major portion fw of the blade, the turnedup forwardedge portion a; of the blade, as particularly shown in the view, Fig. 3,standing and moving substantially in or parallel with the plane ofrotation of the fan, while the turned-up portion y at the rear edge ofthe blade stands at a still greater angle to the plane of rotation ofthe fan than does the blade proper, or, in other words, it stands at ornearly at a right angle to the plane of rotation of the fan.

With reference to ,Fig 3 it will be seen on noting the formation of thefan-blades and their relation to the axis and plane of rota-- tion ofthe fan and to the longitudinal passage through the cylindricalfan-closing casing, the axis of which is coincident with that of thefan, that the forward edge portion of each blade, being inclined intothe plane of rotation, sharply cuts the air, permitting an unobstructedand easy movement. The inclined side of the blade then forces the airoutwardly toward the open end of the cylinder, and, instead of aconsiderable portion of the air propelled by said obliquely-arrangedfan-blade being sheared off obliquely against the inner side of theinclosing cylindrical casing by the rearward edge y of the bladeinclined into the direction of the axis and at right angles to the planeof rotation, the air is forced out of the cylinder in a directionsubstantially parallel with the axial line of the fan, and the turned-npend portion z of the blade, the inclination of which tends toward theplane of rotation, as does the forward edge w, renders the blade thebetter adapted to cleave the air in its forward rotary motionand'insures a gradual guiding of the air upon the propelling portionofthe blade comprised in the said intermediate portion w and therearwardly-inclined edge y.

Besides the increased efficiency of the blade for the purpose of forcingair, due to the blade being formed "from a single piece of metal havingits edge portions at its sides and outer end turned up, from suchconstruction alsc ensues .a greatly-increased rigidity of the blade, andunder such construction the blades may be made of very thin sheet metaland yet possess such stiffness as will withstand all pressure to whichthey may be subjected.

lVhat l claim as my invention isl. A rotary fan having its blades setOb- I fan, and having its rear edge' turned at a' greater angle to theplane of rotation than is the principal intermediate portion of theblade, substantially as described, and for the purpose set forth.

2. A rotary fan having its blades set. 0bliquely to its axis, and havingthe forward longitudinal edge portion and end portion of each bladeturned toward or into the plane of rotation of the fan, and having itsrear edge 1o turned at a greater angle to the plane of r0- tation thanis the principal intermediate portion of the blade, substantially asdescribed, for the purpose set forth.

BENJAMIN F. PERKINS.

Witnesses:

WM. S. BELLoWs, G. M. CHAMBERLAIN.

